This invention pertains to lubricants and greases containing mixed bases, including bases composed of nanoparticles or phenates/sulfonates containing mixed bases or both, wherein the mixed base is composed of, for example, carbonate such as calcium carbonate, a carboxylate such as calcium carboxylate, a phosphate such as tricalcium phosphate, and/or calcium sulfate.
Lubricant oils and greases are commonly used for a variety of applications. For example, lubricant oils are used as crankcase lubricants for internal combustion engines, including gasoline and diesel engines. With the current and anticipated emission regulations, automotive manufactures have been conducting research to develop exhaust aftertreatment devices and other mechanical features to meet the new lower emissions standards. Engine oil is affected by these regulations in that it will need to have significantly lower levels of phosphorous in order to avoid the harmful effects over time on the new exhaust aftertreatment devices. This is a problem for the engine oil formulator because for decades zinc dithiophosphates have been the primary anti-wear additive used for engine oils. Reducing the level of phosphorous in engine oil requires a similar reduction in zinc thiophosphates or other phosphorous-containing anti-wear additives. The inventor has identified that a need exists to provide a solution to this problem.
In addition, various additives can be added to lubricating oils in order to improve various oil properties. Anti-wear agents are intended to decrease wear of machine parts. Additives have been and continue to be developed for use in such oil compositions to improve the lubricating characteristics thereof and thereby to lessen the wear of the moving parts.
Lubricating oils tend to deteriorate under the conditions of use in present day automotive engines, with attendant formations of sludge and lacquer and resinous materials which adhere to the engine parts, thereby lowering the operating efficiency of the engine. Detergents and dispersants are added to the lubricating oil to keep the deposit forming materials suspended in oil so that the engine is kept clean and in efficient operation condition for extended periods of time.
Some common additives used in lubricating oils are metal sulfonates and phenates. In many cases, these additives are overbased, that is, contain a molar excess of base over that needed to neutralize the sulfonic acid or phenolic material. Overbased metal sulfonates are commonly used in lubricating oil compositions as rust inhibitors and detergents. Overbased phenates, including sulfurized phenates, are commonly used in lubricating oil compositions as detergents and antioxidants.